A New Fern Pest.--According to the _British Fern Gazette_ a new pest
threatens the specimens of those who collect living plants. This is the
larva of a small weevil which gets into the stipes of the ferns and
burrowing downward into the heart of the rhizomes soon cause the death
of the plant. The weevil is of Australian origin, probably introduced
into Britain with imported plants. Its scientific cognomen is _Syagrius
intrudens_. At first its depredations were confined to ferns under
glass, but more recently it has taken to the ferns in the wild state.
This, however, is not the only enemy of the ferns that British growers
have to contend with. Another small beetle known as the vine weevil
(_Otiorhyncus sulcatus_) is fond of the plants both in the adult and
larval stages, but the newcomer has already developed a reputation for
destructiveness that places it first as a fern pest.
Walking Fern and Lime.--Nearly everybody who cultivates the walking fern
(_Camptosorus rhizophyllus_), thinks it necessary to supply it with a
quantity of old mortar, quick-lime or pieces of limestone under the
impression that the fern cannot live, or at least cannot thrive without
a considerable amount of calcium in the soil. As a matter of fact it has
been reported on sandstone, shale, gneiss and granite and may possibly
grow on others. Its noticed preference for limestone is apparently not
due to its dependence on calcium but rather to the fact that it is more
nearly adjusted to the plant covering of limestone rocks than it is to
others. It will grow in any good garden soil, but in such situations it
must be protected from its enemies, the ordinary weeds of cultivation,
which otherwise would soon run it out. The same thing is true of many
plants besides ferns. The cactus plant that cheerfully endures the
intense insolation and frequent drouth of the sand barrens, succumbs
very soon to the grass and weeds when planted in rich soil.
Stipe or Stipes.--When it comes to the designation of the stalk of a
fern leaf, there is a wide difference in the way British and Americans
regard it. Americans invariably speak of a single stalk as a stipe and
they may be somewhat astonished, upon referring to a dictionary, to find
that while stipe is given as a legitimate word, it comes direct from the
latin _Stipes_ which the Britons, with perhaps a more classical
education, are accustomed to use. In America the plural of stipes is
stipes or, rather, the plural of stipe is stipes; but in England the
plural of both stipe and stipes is _stipites_. In certain uncultivated
parts of our own country the singular form of the word species is given
as specie; but when we smile at some countryman's description of a
specie of fern, our merriment may be somewhat tempered by the thought
that we still say stipe instead of stipes. If we could only believe that
we use stipe with full knowledge of its derivation, it would not seem so
bad, but it is very evidently a case of plain ignorance.
Apogamy in Pellaea.--Apogamy, or the production of a new sporophyte from
the gametophyte without the union of egg and sperm, used to be
considered a rather rare phenomenon, but as more study is given the
matter, it begins to seem fairly common. Several years ago Woronin
reported apogamy in _Pellaea flavens_, _P. niveus_ and _P. tenera_ and
still more recently W. N. Steil of the University of Wisconsin reported
the same condition in our native _Pellaea atropurpurea_. In Steil's
specimens the young sporophytes were borne on the prothallus lobes near
the notch. The same investigator is now working on apogamy in other
species. A note in a recent number of this magazine asked for spores of
_Pellaea gracilis_ (_Cryptogramma Stelleri_) for this purpose.
Lycopodium lucidulum porophylum.--In the _Ohio Naturalist_ for April
Prof. J. H. Schaffner devotes several pages to a discussion of the
specific distinctness of forms allied to _Lycopodium lucidulum_ and
comes to the conclusion that _Lycopodium porophylum_ is a good species.
If one is to judge by appearances alone, there can be no question as to
_L. lucidulum_ being different from _L. porophylum_ but if the different
appearances that plants put on under different conditions of warmth,
light and moisture are to be considered then there are a number of fern
species in this country in need of a name. Compare _Woodsia obtusa_
grown on a sunny cliff with the same species grown on a moist one, or
_Equisetum arvense_ in woods and on railway banks. Nobody at present can
say positively whether the form called _porophyllum_ is a species or
not. If it can be grown in moisture and shade while still retaining its
characters, or if its spores will produce plants like the parent when
sown in moist shades, then the case should be considered closed.
Meanwhile, if one were to imagine a dry ground form of _L. lucidulum_
what kind of a plant would he construct? Perhaps prostrate stem shorter;
branches in a denser tuft, shorter; leaves less notched, smaller; whole
plant yellower. Well, that is the description of _L. porophylum_!
Affinities of Taenitis.--The genus _Taenitis_ is one that has always
puzzled botanists. It was once placed in the tribe Grammitideae along
with such genera as _Notholaena_, _Brainera_, _Meniscum_, _Vittaria_,
_Hemionitis_ and _Drymoglossum_, and it has also been considered
sufficiently distinct to stand as the type of a tribe named for it,
while recently it has been considered as a member of the tribe
_Polypodicae_. Now comes E. B. Copeland in the _Philippine Journal of
Science_ and gives the genus another turn and this time places it in the
Davallieae largely upon the relationship shown by the internal structure
of the stem and the character of the scaly covering. It is likely that
the new manipulator of the genus is as near right as anybody. The main
thing is to discover what are the real indications of relationships.
With some students it is venation, with others the shape and position of
the indusium, with others the character of the vestiture and still
others may have other rules by which to judge. When we agree upon the
proper earmarks, anybody ought to be able to put the ferns in their
proper groups.
Sporophyll Zones.--The fact is well known that some of the club-mosses,
notably the shining club moss (_Lycopodium lucidulum_) and the fir
club-moss (_L. Selago_), bear their sporangia in bands or zones that
alternate with regions on the stem in which there are no sporophylls,
but it does not seem to be equally well recognized that the same
phenomena are found pretty generally among the ferns. If one will
examine the crowns of the cinnamon fern, it will be readily seen that
sporophylls and vegetative leaves form alternating circles. Curiously
enough, the fertile fronds, which appear at maturity within the circle
of sterile leaves, really belong to the outer circle, as befits the
group that is to develop first. The sensitive and ostrich ferns are
other species in which the zones of fronds are very distinct. So
pronounced is this, and so far has each kind developed before unfolding,
that each is usually incapable of taking up the functions of the other
in cases where the destruction of one kind makes such exchange necessary
or desirable. From efforts on the part of the plant to supply vegetative
tissue to leaves designed originally for spore-bearing, only, we owe the
various "obtusilobata" forms occasionally reported. The differences in
zonation here mentioned are most pronounced in ferns with dimorphic
fronds, but evidences of the same thing, more or less distinct may be
found even in those ferns that have the fertile and sterile fronds
essentially alike in outline. As a usual thing, the spore-bearing leaves
are produced after the vegetative leaves have unfolded and when we find
a plant in full fruit in late summer, that lacked spores in spring, it
is due to the developing of the fertile leaves later. This is especially
true and most noticeable in ferns that produce their fronds in crowns,
but even in those species with running rootstocks, we commonly find
evidences of zonation. Following out the idea of zonation we find among
many of the fern allies that not only are the sporophylls assembled in
zones but the zones terminate the central axis or branch. Under such
circumstances the shoot begins to take on many of the characteristics of
the flower and if we allow the definition of a flower as a shoot beset
with sporophylls, it really is a flower. In the plants in which the
flower comes to its highest development this structure is essentially a
group of two kinds of sporophylls set round with sterile leaves called
petals and sepals. Did ferns, instead of selaginellas, produce two kinds
of sporophylls, the whole fern plant with its crown of fronds, would be
very like a flower.